Kursus Experimentele Muziek: Boekdeel 1: Algoritmische kompositie - Stemmingen en Toonsystemen
Hogeschool Gent : Departement Muziek & Drama
|<Terug naar inhoudstafel kursus>||Naar Noot->frekwentie lookup table|
"MICROTONAL MIDI TERMINAL", is wellicht het enige kommercieel beschikbaar programma dat de muzikus toelaat zowat eender welk denkbaar midi-instrument te bespelen in 'JUST INTONATION'!. Ook andere stemmingen zijn via dit programma te programmeren. Meer nog, het programma laat ook toe de centrale toonhoogte waarop een niet-getemperd systeem gebaseerd is te verschuiven tijdens het spel zelf, en dit zonder er de maat bij de verliezen. Ook als teoretisch werkinstrument is het programma heel geschikt, onder meer omdat het toelaat de stemmingen uit te drukken als getalverhoudingen (breuken of ' ratios') als frekwentie-getallen of in cents en zelfs in eenheden eigen aan bepaalde synthesisers. (TUNING UNITS) Elke afzonderlijke stemming kan als een 'bank' gesaved worden via een enkele toets. De files waarin de stemmingen zijn opgeslagen worden bij het oproepen op het scherm getoond. Voor een snelle test, is het ook mogelijk de diverse intervallen van de stemming via de luidspreker van de komputer te laten klinken. Een belangrijke opmerking is evenwel, dat de werkelijk haalbare toonhoogteresolutie niet op alle synthesizers en klankkaarten dezelfde is. Zelden is 14 bit resolutie, ondersteund door de MIDI standaard, echt geimplementeerd in de hardware.
Ook printer-routines werden voorzien:
- Print Current Tuning.
- Print All Tunings in Current File.
- Print All Modes of Current Tuning.
- Print DOS Directory of Tuning Files.
Zoals zowat elk komputerprogramma, is ook deze MMT behept met enkele BUGS:
1. In PERFORMANCE mode, zegt het scherm "Hit any Key to Quit", maar eigenlijk zou dit moeten zijn " Hit the SPACE BAR to leave PERFORMANCE mode". Alleen de spatiebalk vervult immers deze funktie.
2. Wanneer een stemming veranderd wordt tijdens het spelen op het klavier, zorg ervoor dat je geen toetsen ingedrukt hebt, zoniet bestaat er een grote kans dat de betreffende noten blijven hangen. Het veranderen van stemmingen via het midi-klavier ( - PITCH BEND + PROGRAM CHANGE ) werkt goed, zelfs wanneer er toetsen aangeslagen zijn.
3. Een 'ALL NOTES OFF message' kan tijdens een uitvoering slechts via een midi-controller ofwel door op de spatiebalk te drukken op het komputerklavier. Laatstgenoemde metode doet de gebruiker echter de performance-mode verlaten...
Dit programma kan, tegen een geringe betaling (shareware) , verkregen worden via de auteur zelf:
Gebruiksaanwijzing van het MMT- programma:
Volgende tekst is een samenvatting van de oorsponkelijke engelse gebruiksaanwijzing bij het MMT-programma.
SYSTEM REQUIREMENTS: IBM PC,XT,AT,PS/2 or compatible with at least 128K of memory. MMT works with any monitor and most printers. In order to use the Performance features, a Roland MPU-401 (or compatible) MIDI interface must be installed in your computer and you must have at least one MIDI controllable musical instrument that responds to MIDI PITCH BEND messages. Connect the MIDI controller (keyboard) output to the MIDI input of the computer, and the MIDI out from the computer to the MIDI input of the Sound Generators (synthesizer modules). (See FIG.1 - below )
Midi-in Midisynthesizer or sound-
Midi thru Midisynthesizer or sound- midi IN
If your synthesizer has the keyboard and tone generators integrated into one package (a regular keyboard synthesizer), simply connect the MIDI OUT of the synth to the MIDI IN of the computer and the MIDI OUT of the computer to the MIDI IN of the synthesizer. (FIG. 2)
midi in PC
midi out midi in midi out
If you have a MULTI-TIMBRAL synthesizer, set it up with at least four identical voices (For a special effect, you could use all different voices!), each on a different MIDI channel. The MIDI channels should be adjacent to each other (ie: 1-8, 2-6, 9-16, etc.). The exact number of voices required depends on how many tones you want to have sounding at any one time. If you have them to spare, use them all! ( In this present version, the LOW MIDI CHANNEL is always 1, even though the screen may show another channel. This bug will be fixed in the next version.)
The default MIDI channels are 1 - 8. If you wish to use any other range of MIDI channels with MMT, you must first change this program setting. To change the RANGE of MIDI channels that MMT uses in the POLYPHONIC PERFORMANCE mode, select MIDI CHANNEL LIMITS in the PERFORMANCE menu and enter the new values. Whatever your MIDI configuration, set the PITCH BEND RANGE of all voices to be used with MMT to 1 Semitone. This permits the best pitch resolution, and is necessary for accurate intonation. If your synth has any MICROTUNING features built in, turn them OFF, when using MMT, since the program is designed to use Twelve Tone Equal Temperament as a starting point for all tuning operations.
To start using MMT to play in Just Intonation immediately, first make sure that your MIDI setup is configured appropriately, as outlined in the SETUP section of this HELP file. Then, press <ALT> <P> or the <DOWN ARROW> (cursor) key to bring down the PERFORMANCE MENU.
USING MMT WITH A POLY-TIMBRAL MIDI INSTRUMENT
If you have a multi-channel (polytimbral) synthesizer setup with several voices on successive MIDI channels, press <RETURN> or <ENTER> to select the POLYPHONIC PERFORMANCE mode and play normally. If all is set up correctly, your synthesizer should be playing in Just Intonation. Notice the smoothness and resonance of Major chords on C, F and G and minor chords on A and E. Also notice the relative roughness of certain other chords, such as D.
USING MMT WITH SINGLE CHANNEL MIDI INSTRUMENTS
If your synthesizer can only receive information on one MIDI channel at a time, move the cursor (using the DOWN ARROW) to MONOPHONIC PERFORMANCE before hitting RETURN in the PERFORMANCE menu. In this mode, only single lines may be played in Just Intonation (chords will only be properly tuned if POLYPHONIC mode is used on a multi-timbral instrument), so it would be best to set your synth in MONO mode, in order to reduce the temptation to sound more than one note at a time.
NOTE: Polyphonic textures can still be built, even if you are using the MONO mode, by means of ordinary multi-tracking techniques with a Tape Recorder.
MMTs default scale is a 5 Limit semi-chromatic scale, based on the Ptolemaic Sequence (Just Diatonic). Many other scales are available in TUNING FILES included with this Disk. To use these other scales, load a TUNING FILE from the FILE menu. Once a file is loaded, you may quickly switch between the 16 scales of that file and just as quickly, change the Key Center. Further instructions in this regard will be found in the sections describing the FILE and BANK menus, as well as CHANGING TUNINGS and CHANGING KEY CENTER.
At the top of the MAIN SCREEN are seven MENU HEADINGS, corresponding to the MENUS which contain selection items that access most of MMTs operations. (Instructions for use of MMTs PULL-DOWN MENUS follow shortly in the section: ACCESSING MENUS). The main part of the screen shows pertinent information about the TUNING which is currently active. The NOTE line simply shows which synthesizer keys correspond to the various scale degrees. When the TONIC is changed, the order of the NOTES in this line change too.
The RATIO line on MMTs MAIN SCREEN shows the Just Intervals that make up the scale of the ACTIVE TUNING. These numbers describe the FREQUENCY RATIO of each interval in the scale to the TONIC note, which is normally shown as having a RATIO of 1/1 (because it is the same FREQUENCY as itself). These ratios remain the same on the MAIN SCREEN through changes of KEY CENTER, since the important changes are shown instead on the NOTE line. However, these ratios will be altered considerably when the MODE is changed or when the TUNING is edited (both of these operations are explained in the section dealing with EDITING OPERATIONS).
The STEP line shows the sequential order of the intervals in the SCALE. It is provided as a handy reference for staying oriented while scanning vertical columns of data on the screen.
SIZE refers to the number of Equal Tempered Semitones that would approximate the associated interval (RATIO), as measured from the TONIC note. When this value differs from the STEP value above it, MMT adjusts the actual MIDI note value sent for that step.
BEND refers to the PITCH BEND value that is sent before the note is played in order to fine tune it to the Pitch corresponding with the associated RATIO.
CENTS are linear units for measuring the size of an interval. One Equal Tempered semitone is 100 cents wide. One Octave is 1200 cents wide. Thus an interval of 112 cents is 12% sharper than the corresponding Equal Tempered semitone, while an interval of 98 cents is 2% flatter than an E.T. semitone.
The CENTS line shows how many 1/1200ths of an octave each interval in the scale is from the TONIC (1/1).
The FREQ line is provided purely for convenience. The values in this line have no actual effect on the sounds produced by your MIDI instrument. However, they can be valuable to some people in the process of conceiving and building scales, as well as providing handy values that may be useful when tuning other instruments.
The FUNDAMENTAL frequency (that of the TONIC) has a default value of 264 Hz. so that A will be 440 Hz. in a Diatonic (Ptolemaic) scale. The FUNDAMENTAL is easily changed from the EDIT menu, however and all other values on this line will change with it. My favorite FUNDAMENTAL is 256 Hz., since it may be successively divided by 2 until its value is 1, making it a very easy number upon which to base the calculation of intervals by means of RATIOS.
Again, all references to FREQUENCY, including the FUNDAMENTAL, have NO EFFECT on your synthesizer. However, these actual frequencies can be heard on your computers speaker, by means of selections available from the UTILITY menu.
At the bottom of the screen are several small windows that show the status or values of various program parameters. The blank, full width window that is above the two lines filled with smaller windows is the DIALOG window. MMT often uses this window to communicate short messages or prompts and for input of small amounts of data from you. Just below the DIALOG window, at the left of the screen is the MPU MODE window. This window will say "UART", "RESET", or "DFLT" at various times. These messages refer to the Operation Mode of the MPU (MIDI Interface) at the time they are being viewed. DFLT means the Interface is in whatever mode it was in before running the program. RESET is the Normal Power-On Mode. When in this state, MIDI messages are passed through the computer unchanged by the program. In other words, MMT is NOT tuning your synthesizers notes when in RESET mode.
UART is the Mode used during the PERFORMANCE MODE of this program. MIDI Messages received by the computer while in this mode serve as data for the program, which may either send the same messages out again, send completely different or modified messages that are responses to the data, or certain messages may be ignored or excluded from output. All of this depends upon what messages are received and how the program responds to them. MMT only affects your synthesizers tuning when this window shows UART as the active mode. To the right of the MPU window is a short, blank window that is sometimes used to display information in addition to that in the DIALOG window.
The next two windows, in the center of the same line, show the lowest and highest MIDI channels in the range that MMT cycles through in POLYPHONIC PERFORMANCE mode. These limits can be changed by selecting MIDI CHANNEL LIMITS from the PERFORM menu.
At the far right of this same line is a window containing the name of the TUNING FILE which is currently in memory. New, saved files are identified as UNNAMED.
The bottom left window shows the status of LOCAL CONTROL on your synthesizer. When LOCAL CONTROL is ON, your synth responds directly to its own keyboard (if it has one). MMT turns LOCAL CONTROL OFF during PERFORMANCE, so that it may intercept and alter the MIDI stream from your keyboard before it gets to the sound generators. This makes it possible for MMT to trick your synth into playing in Just Intonation.
The FUNDAMENTAL window shows the frequency from which all values in the FREQ line are calculated. This is for theoretical purposes only, and has no effect upon the actual sound that your synth makes, though they may be played on the computer speaker (for use as a tuning reference or a means of checking by ear, whether all is configured properly) from the UTILITY menu. The TUNING window shows the name of the tuning that is currently selected and active.
The TONIC window shows the STEP # of the scale and the NOTE NAME of the MIDI key that is the current TONIC. The values in the TUNING and TONIC windows change whenever the TUNING or TONIC themselves are changed. However, the data in the main part of the screen (describing the tuning) does not always show these changes immediately. This is intentional, since the time required to update that part of the screen could interfere with PERFORMANCE. Whenever you want an update of this information, tap the HOME key and it will be done.
DIALOG BOXES, CHANGING VALUES and ENTERING DATA
When MMT requires user input, it usually shows a DIALOG BOX with field descriptions and highlighted areas showing current or suggested values or blank areas, waiting for input. Alternatively, some messages will appear on the top line of the lower section of the screen, making a special DIALOG BOX unnecessary. If the name of a TUNING, BANK or FILE is to be entered, just type in the text and hit RETURN to continue. If you make a mistake, use the backspace key to go back and correct it, before hitting RETURN. To change VALUES in DIALOG BOXES and in EDITING WINDOWS, either type in the number or use the < + > and < - > keys to increment or decrement the highlighted number.
The computer keyboard may be used for quickly Changing Tunings, Transposing Key Centers, Accessing Menus, Storing and Renaming newly edited Tunings, sounding the Frequencies of the Current Tuning on the computer speaker, Updating the screen as well as for the Data Entry and Selection functions described under ENTERING DATA.
In addition, many program operations can be performed directly (without needing to use the menus) by means of the FUNCTION KEYS. The 16 white keys at the Left of the keyboard correspond to the 16 tunings currently held in memory, while 13 of the white keys to the Right correspond to one octave of a standard musical keyboard ( computer G = musical C, computer ] = musical octave):
1 2 3 4
Q W E R Y U O P [ ]
A S D F G H J K L ; '
Z X C V
The vertical columns under 1, 2, 3 and 4 correspond to Banks A,B, C and D in the Tuning Directory, (viewable from the BANK menu) and the rows of keys, starting with 1, Q, A and Z represent the tunings in those banks. The row of keys starting with G represents the white keys of a piano and the row starting with Y corresponds to the black keys of a piano (or synthesizer!). Pressing one of the Tuning Keys instantly selects the corresponding Tuning as the Current Tuning. All operations will subsequently use this tuning, and its NAME will be seen in the appropriate window, near the bottom of the screen. The screen can be updated to show the new Tuning Data which is currently in effect, by pressing the <Home> key. If one of these Tuning keys is pressed while holding down one of the <Shift> keys, the opposite operation is accomplished: The CURRENT TUNING and its NAME are placed in the corresponding BANK location, without changing the tunings CURRENT status. Pressing one of the keys corresponding to the musical keyboard instantly changes the TONIC or KEY CENTER of the tuning to the musical step represented by that key. If one of these Music keys is pressed while holding down a <Shift> key, the Frequency of the corresponding step in the Current Tuning is sounded on the computer speaker. When the <Alt> key is held down, pressing certain keys will bring down corresponding menus for the selection of various program operations. These keys are indicated by the highlighted character in each of the corresponding Menu Headings at the Top of the MAIN SCREEN. The Arrow (cursor) keys, to the right of the main computer keys, are used to move the cursor around at various times (see ENTERING DATA), as well as to bring down certain menus (see MENU OPERATIONS). <Return> and <Enter> are normally used for making final selections from menus and for ending lines of Data during DATA ENTRY procedures. <Esc> is usually used to get out of various operations, without having to execute them ( In some procedures, this is accomplished by typing <Q> instead).
Pressing a Function Key on the Computer Keyboard will immediately execute a corresponding operation, without having to go through a menu selection process:
KEY ALONE SHIFT ALT
==== |============= |====================|========================
F1 | HELP MENU | CALL for HELP | DOS Directory of
| | | Tuning Files on Disk
F2 | PUT TUNING | SAVE TUNING FILE | PASTE TUNING BANK
| into a BANK | |
F3 | BEGIN POLYPHONIC PERFORMANCE MODE
F4 | BEGIN MONOPHONIC PERFORMANCE MODE
F5 | BEGIN POLYPHONIC MIDI MONITOR / PERFORMANCE MODE
F6 | BEGIN MONOPHONIC MIDI MONITOR / PERFORMANCE MODE
F7 | EDIT TUNING | RENAME TUNING | NAME TUNING BANK
F8 | CHANGE MIDI CHANNEL LIMITS | PLAY SCALE ON COMPUTER
F9 | GET TUNING | LOAD TUNING FILE | COPY TUNING BANK
F10 | QUIT | QUIT IMMEDIATELY | OPERATING SYSTEM SHELL
At the top of the MAIN SCREEN are seven MENU HEADINGS, corresponding to the MENUS which contain selection items that access most of MMTs operations. These MENUS may be selected by holding down the ALT key and pressing the key corresponding to the highlighted letter in the heading for the desired menu. Once a menu is selected, the cursor (arrow) keys on the numeric keypad are used to select the item desired. Pressing the Down arrow moves the highlight down one menu item, while pressing the Up arrow moves the highlight up one item. Pressing a Right or Left arrow will move you to the next adjacent menu. When the desired menu item is highlighted, press RETURN or ENTER to begin the operation. Pressing ESCAPE instead will return you to the MAIN SCREEN without taking any other action. Most operations may be aborted, should you decide not to go through with them. Usually, this is accomplished by pressing the <ESC> key. At other times there may be a prompt, telling you to hit <Q> to abort the operation.
Menus may also be accessed directly from the arrow keys. Normally, the Left arrow will bring down the FILE menu, the Up arrow will bring down the EDIT menu, the Down arrow accesses the PERFORM menu and the Right arrow brings the HELP menu. From these menus the cursor keys may be used as normal, to move to adjacent menus and select items.
From this menu, You can Load, Save, Rename and Initialize TUNING files, see the DOS directory of TUNING files on disk, access the DOS SHELL or Quit the program. Using the UP/DOWN arrow keys, select the operation that you wish
to perform and press <RETURN> to execute. Pressing <ESC> will bring you back to the MAIN SCREEN. LOAD TUNING FILE is the 1st available selection. If you press <RETURN> at this selection the TUNING FILES in the current DOS directory will be shown on screen and you will be prompted to type in the name of the file that you wish to load. Type only the part of the File name to the left of the period, as shown in the DOS directory. DO NOT type the period or the suffix ( TUN ). After doing this, hit <RETURN> and the File will be loaded into memory. You will then be prompted to select a tuning from the file. 1st, hit the BANK letter ( a..d ) then the Tuning number (1..4), or simply hit <Q> to keep the currently active TUNING. SAVE TUNING FILE lets you save the 16 tunings currently in memory to a disk file. You will be asked if You wish to RENAME the file before saving. If You type <Y>, you will be prompted for the NAME you wish to save the file under. Type only the NAME of the file. Do NOT type the period or DOS suffix. The file will be saved and You will be returned to the MAIN SCREEN. NAME TUNING FILE lets you give the collection of tunings in memory a FILE NAME and optionally save the collection to disk as a file.
INIT TUNING FILE initializes all tunings in memory to be identical with the CURRENT TUNING (the tuning shown on the MAIN SCREEN). This can be useful for creating a group of closely related tunings, to be edited individually afterward. Before this operation executes, You will be given an opportunity to SAVE the current TUNING FILE. DIRECTORY: *.TUN lets you view the TUNING FILES in the current DOS directory.
OP SYSTEM SHELL allows you to perform DOS operations, without leaving MMT. When you choose this selection, the screen will clear and You will be prompted to enter a DOS command. This can be any normal DOS command or any executable file name, so long as a copy of COMMAND.COM as well as the desired program are located in the current DOS directory.
With this feature You can change directories, copy, rename or delete files, run a Sequencer or Patch Librarian or any other number of things.
Whenever a command or program is finished, the prompt will return and another command or program may be executed. When you wish to return to MMT, type: EXIT. You will then be returned to the MAIN SCREEN and everything will be just as it was before you entered the shell. QUIT does what it says, after first giving you a chance to change your mind, and to save the current TUNING FILE, if You wish.
DIRECTORY OF BANKS lets you see the names and locations of the 16 tunings currently held in memory. These are organized into 4 BANKS, identified by the letters A, B, C, D. Each Bank contains 4 tunings, numbered 1,2,3,4. GET TUNING FROM BANK shows the BANK DIRECTORY (as in the last paragraph, above) and then prompts you to select a TUNING. This is done in two steps: First, enter a letter ( A - D ) to select a BANK, then enter a number ( 1 - 4 ) to select a tuning from the selected BANK. The operation may be aborted by typing <Q> instead of a BANK letter.
PUT TUNING IN BANK lets you insert the current TUNING (shown on the MAIN SCREEN) into a bank. The Directory is shown, as in the last two operations described. Then You are prompted to select a BANK letter and tuning number corresponding to the place where you wish to store the Current Tuning. This will replace the Tuning that is already there. Type <Q> to abort the operation.
COPY TUNING BANK selects a whole BANK of tunings to be stored in a buffer. This BANK can subsequently be PASTED over any other BANK, any number of times, until it is replaced with another call to COPY TUNING BANK. With this and the complimentary PASTE TUNING BANK function, BANKs can be prepared and copied between any number of TUNING FILES.
PASTE TUNING BANK is the compliment to COPY.. BANK. Use it to replace any BANK in any TUNING FILE with the BANK stored in the BANK BUFFER, through a call to COPY TUNING BANK.
NAME TUNING BANK allows You to assign a name with up to 12 characters (including numbers, spaces and punctuation) to any TUNING BANK in memory. When a TUNING FILE is saved, the names given to the BANKS, as well as to the tunings and the file itself are stored with it. Alternatively, messages and other information may be stored with a file, to be viewed in the area normally used for BANK names.
Operations accessed from this Menu affect the CURRENT TUNING.
This is the tuning whose data is normally visible on the MAIN SCREEN and which affects the intonation of Your synthesizer when in PERFORMANCE mode.
EDIT TUNING: Select this item to change one or more of the Ratios in the Current Tuning. Using the cursor (arrow) keys, move the highlighted rectangle to the number in the interval that You wish to change. Type in the new number or use the <+> and <-> keys to increment or decrement the selected number. Then go to the next number that You wish to change and repeat the process. Notice that when you move to a new number, the values in the windows below the Ratio change to correspond to the new interval. Repeat until satisfied and hit <RETURN> when done. You will then be given an opportunity to rename the Tuning, if You wish and to optionally install it in a BANK.
NAME TUNING: lets you assign a name, up to 12 characters long (including numbers, spaces and other symbols) to the Current Tuning. Just type it in at the prompt, then hit <RETURN>. The new name should appear in the TUNING window near the lower right of the MAIN SCREEN.
INIT TUNING: lets you reset the values of the Current Tuning to the Default, 5 Limit, semi-chromatic Just Scale.
ADD INTERVAL and SUBTRACT INTERVAL are calculator routines that let you do arithmetic with Ratios. Follow the prompts to enter the values for the two ratios to be added or subtracted (The values are actually multiplied or divided, but You don't have to worry about that), pressing <return> after each entry. The new Ratio will then be displayed with related information such as Cents, Frequency, Semitones, Pitch Bend and Yamaha Tuning Units. Prompts will then appear giving you the option of inserting the new interval into the Current Tuning. If you answer <Y> It will ask whether You want it to be put into the part of the scale corresponding to its approximate semitone value (already calculated) or in some other part of the scale.
TRANSPOSE: works similarly to the above Arithmetic routines, except that the entire scale is transposed up or down by the Ratio that You specify. If the Top number of the Ratio is larger than the bottom number, the scale will be transposed up. If the top number is smaller than the bottom number, the scale will be transposed down. The transposed intervals will normally be placed in the scale so that the semitone values are consistent with those of the source scale, however you will be asked whether you want MMT to do this. If You answer <N> to this prompt, You will be asked Which Note (step) to start the scale on. If you simply hit <RETURN> at this
point, The scale will start at Step #0 (the TONIC).
MODE CHANGE: This does not affect the way the scale sounds, but does significantly change the way it looks. The scale is recalculated to show the intervals for each step of the scale, when the selected step is taken as TONIC.
Before this routine executes, it asks whether you would like all of the 12 possible Modes of the Current Tuning to be Calculated and stored in BANKS A - C. If you answer <Y> An opportunity will be provided to save the current set of 4 TUNING BANKs to a disk file. If so, You will also be offered an opportunity to Simultaneously Print a Chart of the 12 Modes of the Current Tuning. If you answer <N> to the "Calculate all Modes?" prompt, You will be asked which Mode of the Current Tuning to calculate. The new Mode may then be optionally renamed and stored in a BANK.
FUNDAMENTAL FREQUENCY: lets you change the Theoretical Frequency that the Ratios of the tuning refer to. This is for theoretical use only and does not affect the MIDI output of MMT. It does however, affect the actual sounds emitted by the Computer speaker, when the Speaker functions are executed.
From this menu, select from the four different PERFORMANCE modes, or specify the MIDI channels that MMT will cycle through in POLYPHONIC PERFORMANCE MODE. Be sure to read the information under the HELP topic: PERFORMANCE, in addition to the following:
POLYPHONIC... Selecting this item will put MMT into the POLYPHONIC PERFORMANCE mode. In this mode, notes played on the MIDI keyboard are adjusted to produce the Just Intervals of the Current tuning. When more than one note is played at the same time, MMT assigns each note to a different MIDI channel, so that each note gets its own necessary amount of PITCH BEND, without interfering with the tuning of any other notes. The MIDI channels used for this are determined by the MIDI CHANNEL LIMITS, which may also be changed from this menu. This is the normal performance mode for playing Justly tuned Chords and melodies on multi-timbral instruments. This mode does not work with instruments that only receive on one MIDI channel at a time (MMTs MONO mode should be used with those instruments).
MONOPHONIC... This mode acts similarly to the POLYPHONIC mode, adjusting the pitch of all notes to sound the Just Intervals of the current tuning, except that each note is played on the same MIDI channel that it is received on. This is the mode to use with synthesizers that only receive on one MIDI channel at a time.
Only one note at a time should be played on any single MIDI channel in MONOPHONIC mode, if the Just tuning is to be preserved, since MIDI PITCH BEND affects all notes on any one channel together (eliminating the possibility of tuning Just intervals other than octaves and perhaps, 5ths).
Two or more single channel synths (or two or more channels of a multi- timbral synth) can be played simultaneously in MONO mode, provided that each is set to receive on a different MIDI channel. This might occur if data from an external sequencer is played through MMT on its way to the synths.
POLYPHONIC (MIDI stream shown on screen). This works identically to the regular POLYPHONIC PERFORMANCE mode, with the added feature of a real time MIDI monitor displayed on screen. Data coming into MMT is shown on the left side of the screen, while the corresponding data that has been changed in order to accomplish the Microtuning is displayed on the right side of the screen.
MONOPHONIC (MIDI stream shown on screen) is the compliment to the POLYPHONIC mode, just described.
Both of these PERFORMANCE modes with the built in MIDI monitors are very useful for gaining insight into the way that MMT works. These modes can also be very useful for learning more about your MIDI system, as well. It takes time to write to the computer screen, however and if you are playing lots of notes pretty fast, the monitor function could cause noticeable delays in the MIDI output. This can be used for a special effect, but if you want precise timing the regular performance modes may be more suitable for general use.
MIDI CHANNEL LIMITS. Selecting this item brings up a Dialog Box that lets You change the values for the High and Low MIDI channels between which MMTs POLYPHONIC PERFORMANCE modes will operate.
The highlighted value may be changed by either typing in the desired number or by pressing the <+> or <-> keys. The highlight can be moved to the other number by pressing either the UP or the DOWN arrow keys. When the new values have been entered, press <RETURN>. The new MIDI channel limits should then be visible in their respective windows near the bottom of the MAIN SCREEN.
NOTE: In this present version, MMTs Low MIDI channel is always channel 1, regardless of what You set it to or what it says in the window. This bug will be fixed in the next version. The High MIDI channel however, really is the one indicated in the window and may really be set to any one of the 16 possibilities.
PLAY SCALE ON COMPUTER SPEAKER: When this option is selected, a scale will be played on the computer speaker, consisting of the FREQUENCIES shown on the MAIN SCREEN for the current tuning. Each tone will last approximately 1 second and will be identified on the DIALOG LINE of the MAIN SCREEN, as it is played.
SOUND FUNDAMENTAL FREQUENCY ON COMPUTER SPEAKER: When this item is selected, the FUNDAMENTAL FREQUENCY, as shown on the MAIN SCREEN will be sounded on the computer speaker and held until a key is pressed on the computer keyboard.
NOTE: The same computer keys that are used to change Key Center may also be used to play the individual frequencies on the computer speaker, if <Shift> is held or <Caps Lock> is pressed.
SHOW YAMAHA TUNING UNITS: The Yamaha TU values required to enter the current tuning into a DX7II or TX81Z will be shown at the bottom of the MAIN SCREEN. This is for convenience. MMT does not transmit this information to the synthesizers, over MIDI.
NOTE: Be sure printer is connected, turned on and ready for use.
PRINT CURRENT TUNING: The 12 Ratios of the Current Tuning will be printed, along with the Name of the Tuning.
PRINT ALL MODES OF CURRENT TUNING: A nicely formatted sheet will be printed, showing the Note Names, Step Numbers, Cents, Frequencies and Ratios of the Current Tuning, as well as the Ratios for the 11 other Modal possibilities that occur when 1/1 status is conferred upon each of the other scale degrees.
PRINT ALL TUNINGS IN CURRENT FILE: A 2 page chart is printed, showing the Names and Ratios of the 16 tunings, currently in memory. The Tunings are organized to show their BANK and Number locations, and the NAMES of the BANKS, as well as the FILE are indicated plainly.
PRINT DIRECTORY OF TUNING FILES: Prints list of files on disk.
While most operations are accessible from the PULL-DOWN MENUS, certain keyboard shortcuts are available to save time and effort. Holding down the ALT key and pressing <B> accesses the BANK MENU. Pressing <RETURN> will bring up the DIRECTORY OF TUNING BANKS. If the item GET TUNING FROM BANK is selected instead, the DIRECTORY is followed with the prompts to select a TUNING from one of the BANKS. This is accomplished by first pressing a letter key (A,B,C,D) to select the BANK, then pressing a number key (1,2,3,4) to select the TUNING from that BANK. The operation may be aborted by typing <Q> instead.
Alternatively, the sixteen left-most white (computer) keys may be struck at any time (except during menu operations) to instantly select any tuning from the current TUNING FILE. This change of the CURRENT TUNING may be verified by the new TUNING NAME seen in its appropriate window in the bottom right portion of the screen. The new TUNING will be active immediately, but the screen data will not show immediately, because the time needed to update the screen could interfere with a performance. To update the part of the screen which shows the new TUNING DATA (which takes about 1 second), tap the HOME key.
Each vertical column of four keys represents a TUNING BANK, as it appears in the DIRECTORY OF BANKS, accessible from the BANK menu. The column under the <1> key corresponds to BANK A, the column under the <2> key corresponds to BANK B, <3> = BANK C and <4> = BANK D. Thus, pressing the <A> key selects TUNING #3 from BANK A, key <E> selects TUNING #2 from BANK C and <V> selects TUNING #4 from BANK D.
These same computer keys may be used to instantly store the CURRENT TUNING in the corresponding BANK locations if the SHIFT key is held while striking them. (No prompt for renaming will appear when this method is used to store tunings). TUNINGS may also be stored in BANKS by selecting PUT TUNING IN BANK at the BANK menu. RENAMING tunings is also possible. This Item is selected from the EDIT menu.
CHANGING KEY CENTER
The scale can be transposed to another Key Center by tapping certain computer keys. (It is also possible to do this from your MIDI controller. This is explained in the HELP section on PERFORMANCE. Starting with <G>, and progressing to the right, one octave of a music keyboard is simulated on the computer keyboard, with the "white keys" represented by <G>,<H>,<J>,<K>,<L>,<;>,<'>,<]>, and the "black keys" represented by <Y>, <U>,<O>,<P> and <[>. Pressing one of these keys transposes the scale so that it starts on that key Center. For instance, you are playing in the key of C (the default tonic) and you wish to modulate to the key of G. Play normally until you are ready to make the switch, then simply tap <L> on the computer keyboard. You may now play normally in the key of G and all notes will be in perfect tune.
Y U O P [
COMPUTER KEYS: G H J K L ; '
C# D# F# G# A#
MIDI KEYS: C D E F G A B
Pressing one of these keys at any time (except during MENU operations) instantly changes the TONIC of the CURRENT TUNING. This may be verified by observing the new KEY CENTER in the TONIC window in the lower right portion of the MAIN SCREEN. To see the new relationships of the tones, strike the HOME key, which updates all screen information. In case you are new to Just Intonation, all notes in a given scale are related to a specific note which is considered the TONIC and has a frequency ratio of 1/1. Likewise, every note in a scale has a unique relationship to every other note in the scale, making it necessary to transpose the scale when changing Key Centers. (See the section "ABOUT RATIOS" for more on this subject). Additional, related functions are also available from the PULLDOWN MENU under the EDIT heading. The same computer keys that are used for changing the key center may also be used to sound the corresponding frequency on the computer speaker. This is done by holding the SHIFT key, while pressing them.
There are two different Performance Modes:
1 : Polyphonic,(each new note going to a different MIDI channel, with a variable # of channels).
2 : Monophonic, (one voice on any single MIDI channel).
Both modes send specific amounts of Pitch Bend for each note. There are two versions of each of the performance modes, one writing to the screen and another that does not. The versions that show operations on the screen are very helpful for study, but may be too slow for real time performance. For normal playing, use the versions that don't write to the screen. These modes may each be entered directly by pressing F3, F4, F5 or F6. These PERFORMANCE modes are for use with EQUAL TEMPERED instruments, in order to force them into Just Intonation. To use them with Microtuneable instruments, the Microtune feature of the instrument must be turned OFF. However, Microtonal instruments may be played normally (unaffected by the program) from any other menu or screen, or if they are set to receive on channels outside of the MMTs current range settings (see next paragraph).
The TUNING FILE named EQUAL.TUN on the program disk contains a tuning called 12 TONE ET, which does not retune the synth at all. If for some reason you want to use your synths microtuning abilities while in MMTs PERFORMANCE mode, use this tuning. Press <F8> to set the Lowest and Highest MIDI channels for the POLYPHONIC mode to circulate through. Be sure that your instrument(s) are set to receive on corresponding channels. (It does not matter what channel your instrument(s) sends on, however).
With MMT, You can play your instrument live in any tuning that you desire. Just Load a Tuning File, select a tuning from one of the Banks (or construct one), go to PERFORMANCE MODE and play!
CHANGING the TONIC, that is the note upon which all others in the scale are referenced, may be accomplished in two different ways: Either tap one of the appropriate computer keys (see CHANGING KEY CENTER) or tap the PITCH BEND control in the positive direction and then play the key on your MIDI controller that you wish to use as the New Tonic. To SELECT a NEW TUNING during performance, either strike one of the appropriate computer keys (see CHANGING TUNINGS) or tap the PITCH BEND control in the Negative direction and then send a PROGRAM CHANGE message, corresponding to the order in which the tuning is listed in the current TUNING FILE. When changing TUNINGS or KEY CENTER during performance, the corresponding message on the screen will change, too. A blank window in one of these areas means that MMT is waiting for your selection. PITCH BEND and CONTINUOUS CONTROLLERS do not work in the normal way, with MMT, but the SUSTAIN PEDAL does. To EXIT PERFORMANCE MODE, send a MIDI STOP message from your controller, or hit the <Space Bar> on the computer. In order to trick Equal Tempered synths into playing Just Intonation, PITCH BEND cannot work in the usual way, with MMT. If you want to add dynamic pitch bend to your performance, it is suggested that you first record a sequence (on an external sequencer) using MMT in MONOPHONIC mode,then add a control track with the pitch bend on the appropriate MIDI channel. If you do this, it is advised that the PITCH BENDing stop before the last NOTE ON of a phrase, since the last PITCH BEND value will otherwise counteract the tuning offset implemented by MMT. Alternatively, make shure that the last PITCH BEND value that you enter is the same value as the one put into the sequence by MMT.
RECORDING WITH MMT
Most of your recording techniques will work the same as always with MMT. If you have a Multi-Track tape recorder, you can compensate for the limitations of a single channel (not multitimbral) synthesizer, by recording single lines through MMT on successive tape tracks and then mixing down as usual to produce a polyphonic texture. At times, You may wish to do this anyway, even if you have a multi-timbral instrument because of the increased Timbral possibilities.
USING MMT WITH A SEQUENCER
If you have an external sequencer or a second MIDI computer with sequencer software, playing through MMT will create sequences that may be played back in the altered tuning, without the necessity of using MMT for the Playback, or previously recorded sequences can be converted to the new scales by using the Overdub feature of your sequencer. To do this, hook the MIDI output of the sequencer to the MIDI input of the computer running MMT, and the MIDI out of the Computer to the MIDI in of the sequencer. Turn ECHO OFF on the sequencer, and play the original sequence through MMT onto the new track. This new track will have the microtuning information on it and should be used independently, without the original tracks. More than one track may be created in this way, provided that the MIDI channel ranges for each track do not overlap, and that your instrument(s) have enough voices and MIDI channels to go around.
HOW MMT WORKS
In the absence of a standard Microtuning parameter for MIDI instruments, precise amounts of PITCH BEND have been utilized to pretune each note, before it is sounded. Since MIDI PITCH BEND messages affect all notes on a given channel simultaneously, it is necessary that all notes that are to be sounded at any one time be on different MIDI channels (with the exception of octaves). MMT automatically distributes incoming note information (regardless of the incoming MIDI channel[s]) to successive user selectable MIDI channels, along with the appropriate PITCH BEND data for each note.
OPTIMUM results are achieved with MULTI-TIMBRAL instruments, that allow two or more voices to be controlled independently on different MIDI channels. If your instrument is Multi-Timbral, set each (normally identical) voice on a different (successive) MIDI channel. Several different instruments on different MIDI channels may also be used in this way, provided they are properly connected, either by 'daisy-chaining' or by means of parallel MIDI connections from the computer. A single channel instrument may also be used in the MONOPHONIC PERFORMANCE mode, but only for melodic lines. More than one melodic line may be played at once in MONOPHONIC mode, provided that each is sent and received on a different MIDI channel (this is practical when using MMT with an external sequencer, allowing each melodic line to have a different timbre).
In JUST INTONATION, musical intervals are usually described in terms of the RATIO of their frequency to that of the TONIC note of a scale. Changing the values of the numbers in the ratios alters the frequency of the scale degrees, which changes the sound of the music played with that scale. MMT lets you alter existing scales or make up new ones by specifying the values in the ratios. The interval described by the RATIO is derived by multiplying the frequency of the TONIC by the TOP number in the RATIO and then dividing the result by the BOTTOM number to get the FREQUENCY of the interval.
(Example: If C has a Ratio of 1/1 and G has a Ratio of 3/2, it means that G is three times half the frequency of C.) As a general rule of thumb, the smaller the numbers in the RATIOS of a musical SCALE, the more CONSONANT the intervals will probably sound. Conversely, the larger the numbers in the RATIOS are, the more DISSONANT the intervals are likely to be.
Filedate: 1990-08-19 / 2007-03-24
|Terug naar inhoudstafel kursus: <Index Kursus>||Naar homepage dr.Godfried-Willem RAES||Naar opzoektabel noot-> frekwentie|